index
integer
The Index field is used to ensure a consistent IP-to-DNS name
mapping across all machines within an IMEX domain. Each node's index
directly determines its DNS name within a given NVLink partition
(i.e. clique). In other words, the 2-tuple of (CliqueID, Index) will
always be unique. This field is marked as optional (but not
omitempty) in order to support downgrades and avoid an API bump.